Electrochemical sensor with nano-wire array

Abstract

An electro-chemical sensor comprises a bismuth nano-wire array. The sensor is used to detect incipient corrosion under paint. It is particularly useful in admiralty and marine applications such as for detecting incipient metal oxidation such as rusting and for monitoring the progress of metal oxidation on ship hulls and tanks. It is also useful in the automobile industry for quantifying surface quality in preparation for painting.

1. An electro-chemical sensor comprising:
 (a.) a nano-wire array comprising:
 (i.) an insulating membrane having a work piece contact surface and a base surface and parallel nano-capillaries extending there through, and 
 (ii.) essentially parallel bismuth nano-wires that do not contact each other, each bismuth nano-wire in the nano-wire array extending within a nano-capillary from 0.01 to 0.1 millimeters beyond the work piece contact surface to the base surface, 
 (iii.) each bismuth nano-wire comprising micron size crystals grown in the nano-capillary by electroplating, 
 
 (b.) a bismuth film, coating the base surface and in contact with the bismuth nano-wires, 
 (c.) electric potential measuring means in electrical contact with the bismuth film. 
 
     
     
       2. The electro-chemical sensor of  claim 1  wherein the bismuth nano-wires and the bismuth film are both made from a metal selected from the group consisting of elemental bismuth and bismuth telluride. 
     
     
       3. The electro-chemical sensor of  claim 1  wherein the bismuth nano-wires have a diameter of 8 nanometers to 10 millimeters. 
     
     
       4. The electro-chemical sensor of  claim 1  wherein the bismuth nano-wires have a length of 0.01 to 10 millimeters. 
     
     
       5. The electro-chemical sensor of  claim 1  wherein the insulating membrane is made of a material selected from the group consisting of fiber, polymer, glass, mica and alumina. 
     
     
       6. The electro-chemical sensor of  claim 1  wherein the electric potential measuring means is in electrical contact with both the bismuth film and a work piece, the work piece having on its surface an element selected from the group consisting of iron, aluminum and copper. 
     
     
       7. The electro-chemical sensor of  claim 1  wherein the electric potential measuring means is in electrical contact with both the bismuth film and a ferrous work piece. 
     
     
       8. The electro-chemical sensor of  claim 1  wherein the bismuth nano-wires comprise bismuth (III) crystals having an average size of 1 to 10 microns. 
     
     
       9. An electro-chemical sensor comprising:
 (a.) a nano-wire array comprising:
 (i.) a non-woven fiber insulating membrane having a work piece contact surface and a base surface and a plurality nano-capillaries extending there through, and 
 (ii.) a plurality of bismuth nano-wires, each nano-wire in the plurality of essentially parallel bismuth nano-wires that do not contact each other extending within a capillary from 0.01 to 0.1 millimeters beyond the work piece contact surface to the base surface, 
 (iii.) the bismuth nano-wires comprising crystals grown by electroplating and having an average crystal size of 1 to 10 microns, 
 
 (b.) a bismuth film, coating the base surface and in contact with the plurality of bismuth nano-wires, 
 (c.) electric potential measuring means in electrical contact with the bismuth film. 
 
     
     
       10. The electro-chemical sensor of  claim 9  wherein the bismuth nano-wires and the bismuth film are both made from a metal selected from the group consisting of elemental bismuth and bismuth telluride. 
     
     
       11. The electro-chemical sensor of  claim 9  wherein the bismuth nano-wires have a diameter of 0.1 to 20 microns. 
     
     
       12. The electro-chemical sensor of  claim 9  wherein the bismuth nano-wires have a diameter of 0.1 to 1 microns. 
     
     
       13. The electro-chemical sensor of  claim 9  wherein the bismuth nano-wires have a length of 0.1 to 10 microns. 
     
     
       14. The electro-chemical sensor of  claim 9  wherein the non-woven fiber insulating membrane is nano-porous filter paper. 
     
     
       15. The electro-chemical sensor of  claim 9  wherein the electric potential measuring means is in electrical contact with both the bismuth film and a work piece, the work piece having on its surface a metal element selected from the group consisting of iron, aluminum and copper. 
     
     
       16. The electro-chemical sensor of  claim 9  wherein the electric potential measuring means is in electrical contact with both the bismuth film and a ferrous work piece. 
     
     
       17. The electro-chemical sensor of  claim 9  wherein the bismuth nano-wires comprise sub micron size bismuth (III) crystals. 
     
     
       18. The electro-chemical sensor of  claim 1  wherein the bismuth nano-wires comprise sub micron size bismuth (III) crystals.